This paper evaluates the effect of ergonomic factors on task performance and trainee posture during laparoscopic surgery training. Twenty subjects without laparoscopic experience were allotted into 2 groups. Group 1 was trained under the optimal ergonomic simulation setting according to current ergonomic guidelines (Condition A). Group 2 was trained under non-optimal ergonomic simulation setting that can often be observed during training in a skills lab (Condition B). Posture analysis showed that the subjects held a much more neutral posture under Condition A than under Condition B (p < 0.001). The subjects had less joint excursion and experienced less discomfort in their neck, shoulders, and arms under Condition A. Significant difference in task performance between Conditions A and B (p < 0.05) was found. This study shows that the optimal ergonomic simulation setting leads to better task performance. In addition, no significant differences of task performance, for Groups 1 and 2 using the same test setting were found. However, better performance was observed for Group 1. It can be concluded that the optimal and non-optimal training setting have different learning effects on trainees’ skill learning.
In the last two decades minimally invasive surgery (MIS) has been gaining in acceptance and popularity. Laparoscopic cholecystectomy became a golden standard procedure with proven benefits (Matern, 2009 and Kaya et al., 2008). However, drawbacks of the laparoscopic approach such as lack of tactile perception and limited degree of freedom for manipulating the instruments remain. Therefore, proper design of the instruments and operating room layout has now become more critical in order to avoid fatigue and human errors. The ergonomic factors are thus of increasingly importance for MIS (Berguer, 2006).
Safe performance of laparoscopic surgical procedure requires adequate training preferably in a well-equipped skills lab, within a structural training curriculum. Current states of simulation training in surgery and listing of available modalities have recently been presented (Jakimowicz and Fingerhut, 2009 and Jakimowicz and Jakimowicz, 2011).
Box trainers are highly versatile, relatively inexpensive and offer realistic haptic feedback and are thus attractive for laparoscopic trainings purposes. Basically such a training device consist of a box in which physical objects (like artificial organs) are positioned. The trainee can practice various skills and tasks, such as the eye-hand coordination and camera navigation (Botden et al., 2008).
Depending on the type of training, a variety of objects can be positioned in the box. Novice trainees start practicing by positioning beans; while more advanced trainees perform procedures on artificial, living or cadaver organs/tissues. Lights, instruments and medical appliances can be used to simulate the clinical operating room as good as possible. Because the trainee is practicing on physical structures it is valuable to use the standard clinical instruments so as to experience and train the haptic feedback. For this reason, it is meaningful to investigate the ergonomic factors of the simulation setting with box trainer, with an eye for further improvements of existing modalities.
It is common that many simulation setups in skills labs are sub-optimal from an ergonomic point of view, such as table height that cannot be adjusted, monitors that cannot properly be positioned. Also, the workspace and the target location cannot assure a certain range of intra-corporal/extra-corporal instrument length ratio. Last but not least, the optical axis-to-target view angle is often randomly chosen.
In this research, two performance conditions were set for training and testing subjects. One was an optimal ergonomic condition according to literatures (Hanna et al., 1997, Berguer et al., 2002, Matern et al., 2001 and Emma et al., 2000), and the other was a non-optimal ergonomic condition that can often be observed in the skills lab. The goal of this study is to investigate the influence of ergonomic factors on task performance during laparoscopic training with a box trainer, and to evaluate the trainee posture under these two conditions.
This study shows that the optimal ergonomic simulation setting leads to better task performance. And optimal and non-optimal training setting have different learning effects on trainees’ skill learning. Training under the present optimal ergonomic condition can reduce the physical discomfort and thus, improve the task performance.
Posture analysis showed that the subjects held a much more neutral posture under optimal ergonomic condition. The subjects had less joint excursion and experienced less discomfort in their neck, shoulders, and arms. Optimal ergonomic simulation setting as described in this study should be recommended in skills lab during training.
